Maternal nest quality and its influence on litter survival and weaning performance in commercial rabbits

Two hundred fifty parturition records on measures of maternal nest quality were collected over four seasons (S) from does (d; n = 108) of Californian (CAL), New Zealand White (NZW), and CAL x NZW breed types (DB). Service sires (s; n = 85) were from four sire lines (SL): CAL, NZW, and control and selected synthetics. Sires were nested within SL and 6-mo breeding cycle (C). Nest quality traits included fur weight (FW), nest structure (NS) and fur placement (FP; scores 1 to 5), and kit placement (KP; scores 1 to 4). Additional doe and litter characters studied over eight parities (P) were gestation length, doe body weight at parturition, litter size and weight at birth and weaning, estimated milk yield, doe feed intake, and neonatal and preweaning survival rates (NSR and PSR). A mixed model was used that included SL, C, SL x C, s/(SL x C), DB, SL x DB, d/(SL x DB), S/C, SL x (S/C), DB x (S/C), P, SL x P, DB x P, (S/C) x P, and residual error. Neither SL, s/(SL x C), nor SL x DB influenced (P > .05) nest traits. Nest quality traits did not have normal distributions. Although residual correlations were moderate to high among nest traits studied (.21 < r < .67), correlations relating nest quality to doe and litter traits were low (r < .21). The CAL had lower (P < .05) nest trait scores than NZW purebred does. The NZW does had higher (P < .05) FW (1.9 g) and FP (.36 units) scores than CAL x NZW does. Season, but not parity, influenced (P < .05) NS and KP. From path analysis, relative to other doe and litter characters, nest traits accounted for 21.2 to 35.3% of total variation (across doe breed types) in NSR. However, nest traits had low determination (< 5%) for PSR and litter weaning weight.